System and Method for Segregating Layer Seven Control and Data Traffic

ABSTRACT

A load balancer forwards a content request from a client system to a proxy server, receives from the proxy server a modified content request based on the content request and including information identifying a content origin server, opens a connection with the content origin server in response to receiving the first modified content request, and sends a second modified content request based upon the first modified content request to the content origin server. The load balancer also receives content associated with the content request from the content origin server, and forwards the content to the client system.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to communications networks, andmore particularly relates to a system and method for segregating layer-7control and data traffic.

BACKGROUND

Packet-switched networks, such as networks based on the TCP/IP protocolsuite, can distribute a rich array of digital content to a variety ofclient applications. One popular application is a personal computerbrowser for retrieving documents over the Internet written in theHypertext Markup Language (HTML). Frequently, these documents includeembedded content. Where once the digital content consisted primarily oftext and static images, digital content has grown to include audio andvideo content as well as dynamic content customized for an individualuser.

It is often advantageous when distributing digital content across apacket-switched network to divide the duty of answering content requestsamong a plurality of geographically dispersed servers. For example,popular Web sites on the Internet often provide links to “mirror” sitesthat replicate original content at a number of geographically dispersedlocations. A more recent alternative to mirroring is contentdistribution networks (CDNs) that dynamically redirect content requeststo a cache server situated closer to the client issuing the request.CDNs either co-locate cache servers within Internet Service Providers ordeploy them within their own separate networks. An alternative to theCDN is transparent caching/proxy which does not require a businessrelationship between the network provider and the content owner. Atransparent cache server can be a pure proxy where no content is cached,or can be a caching proxy where the content is cached. The CDN cachesare also referred to as reverse proxies.

BRIEF DESCRIPTION OF THE DRAWINGS

It will be appreciated that for simplicity and clarity of illustration,elements illustrated in the Figures have not necessarily been drawn toscale. For example, the dimensions of some of the elements areexaggerated relative to other elements. Embodiments incorporatingteachings of the present disclosure are shown and described with respectto the drawings presented herein, in which:

FIG. 1 is a block diagram illustrating a communications network inaccordance with an embodiment of the present disclosure;

FIG. 2 is a block diagram illustrating a communications network inaccordance with another embodiment of the present disclosure;

FIGS. 3-6 are lane/flow diagrams illustrating various use cases of thecommunications network of FIG. 2; and

FIG. 7 is an illustrative embodiment of a general computer system.

The use of the same reference symbols in different drawings indicatessimilar or identical items.

DETAILED DESCRIPTION OF THE DRAWINGS

The numerous innovative teachings of the present application will bedescribed with particular reference to exemplary embodiments. However,it should be understood that this class of embodiments provides only afew examples of the many advantageous uses of the innovative teachingsherein. In general, statements made in the specification of the presentapplication do not necessarily limit any of the various claimedinventions. Moreover, some statements may apply to some inventivefeatures but not to others.

FIG. 1 illustrates a communications network 100, such as the Internet,including an autonomous system (AS) 110, a provider network 120, andcontent origin servers 130 and 132. AS 110 includes routers 112 and 114,and client systems 116 and 118. Provider network 120 includes loadbalancers 122 and 124, proxy servers 126 and 128, and a cache server129. Routers 112 and 114 communicate with each other and connect toother ASs through peering points at the routers. Client systems 116 and118 are connected to one or more of routers 112 and 114 and to providernetwork 120 to retrieve information from provider network 120 and fromcontent origin servers 130 and 132. For example, cache server 129 caninclude a web page, a content file, such as graphic, audio, and videocontent, a program file such as a software update, or the like, thatclient system 116 can retrieve from the cache server, and content originserver 130 can include another web page, download content file, programfile, or the like, that client system 118 can retrieve from the contentorigin server.

In a particular embodiment, when cache server 129 includes content thatis requested by client system 116 and 118, the requests are directed toone of load balancers 122 or 124. For example, a request can includelayer-7 control traffic such as a HyperText Transport Protocol (HTTP)connection request that is received by load balancers 122 and 124, and aconnection can be opened between the requesting client system 116 or 118and the receiving load balancer. An example of an HTTP connectionrequest includes a requesting client system 116 or 118 issuing a TCPsynchronization request (SYN), the receiving load balancer 122 or 124responding with a synchronization acknowledge response (SYN/ACK) to therequester, and the requester responding with an acknowledge response(ACK). Collectively, an HTTP connection request can be referred to as aSYN-SYN/ACK-ACK transaction. In turn, load balancers 122 and 124 issuean HTTP connection request to one of proxy servers 126 or 128 and aconnection is opened between the requesting load balancer and thereceiving proxy server. Once a connection is opened the client sends anHTTP request such as a GET message. The receiving proxy server 126 or128 determines if the content is available from cache server 129, and ifso, directs the cache server to provide the requested data to therequesting client system 116 or 118.

In another embodiment, when the content is not available from cacheserver 129, the receiving proxy server 126 or 128 will issue an HTTPconnection request to content origin server 130 or 132 that isdesignated as the content origin server for the requested content and aconnection is opened between the requesting proxy server and thereceiving content origin server. When the connections are opened, therequesting client system issues further layer-7 control traffic, such asan HTTP content request, to the connected load balancer which forwardsthe HTTP content request to the connected proxy server, and the proxyserver forwards the HTTP content request to the connected content originserver. An example of an HTTP content request includes an HTTP GETrequest, an HTTP POST request, another HTTP content request, or acombination thereof. In response to receiving the HTTP content request,the content origin server issues layer-7 data traffic to provide therequested content back to the requesting client system via the connectedproxy server and the connected load balancer. In a particularembodiment, the connections between AS 110 and load balancers 122 and124, between the load balancers and proxy servers 126 and 128, andbetween the proxy servers and content origin servers 130 and 132 areclosed after the requested content is sent to the requesting clientsystem 116 or 118. As such, the connections between one or more of AS110, load balancers 122 and 124, proxy servers 126 and 128, and contentorigin servers 130 and 132 are maintained only until the requestedcontent is delivered to client system 116 or 118. In another embodiment,the connections between one or more of AS 110, load balancers 122 and124, proxy servers 126 and 128, and content origin servers 130 and 132are persistent connections, as needed or desired. For example, becausethe connections between load balancers 122 and 124 and proxy servers 126and 128 are within provider network 120, the connections can bemaintained to handle multiple HTTP content requests. Content originservers 130 and 132 can represent an actual origin server, or canrepresent another intermediate server acting as a content origin server,such as a content transformation server or the like.

FIG. 2 illustrates another embodiment of a communications network 200,similar to communications network 100, including a client system 210, arouter 220, a load balancer 230, a proxy server 240, and a contentorigin server 250. Client system 210 can request content by issuinglayer-7 control traffic such as an HTTP connection request 262. Theconnection can terminate on load balancer 230 which in-turn issues anHTTP connection request 264 to proxy server 240 and a connection isopened between the load balancer and the proxy server and forwards theclient request to proxy server 240. Proxy server 240 determines that therequested content is not available from a cache server, and sends amodified HTTP content request 268 to load balancer 230. In response tomodified HTTP content request 268, load balancer 230 issues an HTTPconnection request 270 to content origin server 250 to open a connectionbetween the load balancer and the content origin server. Load balancer230 then issues modified HTTP content request 272 to content originserver 250.

Content origin server 250 operates to provide layer-7 data trafficincluding the requested content 274 to load balancer 230 over the openconnection between the load balancer and the content origin server. Loadbalancer 230 forwards the requested content 276 to client system 210over the open connection between the client system and the loadbalancer. In this way, the layer-7 control traffic is segregated fromthe layer-7 data traffic, such that proxy server 240 is not burdenedwith the load of the layer-7 data traffic. As such, proxy server 240 canbe sized based upon the bandwidth needed to accommodate HTTP connectionrequest 264, HTTP content request 266, and modified HTTP content request268, and is relieved of handling the network load associated withproviding the requested content 274 to the client. In a particularembodiment, the connections between client system 210 and load balancer230, between the load balancers and proxy server 240, and between theload balancer and content origin server 250 are closed after therequested content 276 is provided to client system 210. In anotherembodiment, the connections between one or more of client system 210 andload balancer 230, the load balancers and proxy server 240, and the loadbalancer and content origin server 250 are persistent connections, asneeded or desired.

Proxy server 240 modifies HTTP content request 266 into modified HTTPcontent request 268 by adding HTTP headers to the HTTP content request,removing HTTP headers from the HTTP content request, or modifying HTTPheaders in the HTTP content request, as needed or desired. For example,proxy server 240 can add, remove, or modify HTTP headers such as contenttype headers, authorization headers, mime type headers, date headers,referrer headers, user agent headers, other HTTP headers, non-standardheaders, or a combination thereof. As such, modified HTTP contentrequest 268 can uniquely identify a user of client system 210, or cancommunicate additional information to origin server 250, such as networkconnectivity or device characteristics of the client system. In aparticular embodiment, proxy server 240 determines a quality of service(QoS) level associated with HTTP content request 266, and adds ormodifies a Differentiated Service Code Point (DSCP) header to reflectthe QoS level. In another embodiment, proxy server 240 provides aforwarding Internet Protocol (IP) address in the place of a destinationaddress of HTTP content request 266, where the forwarding IP address isassociated with one of several origin servers 250, or can provide akeyword associated with the one of several origin servers.

Proxy server 240 also operates to respond to HTTP content request 266with a Universal Resource Indicator (URI) redirect message, such as anHTTP 302 message, to client system 210. For example, proxy server 240can be operated in conjunction with a parental control capability, andcan determine that the requested content is associated with a contentrestriction for a particular user of client system 210. Here, proxyserver 240 can provide a URI redirect that redirects client system 210to a web page that indicates that the requested content is restricted.In addition, proxy server 240 can respond to a request for restrictedcontent by sending a URI redirect message that includes a keyword, suchas “RESET,” to load balancer 230, thereby instructing the load balancerto send a Transmission Control Protocol (TCP) Reset (RST) message backto client system 210, thereby resetting the connection between theclient system and the load balancer. In another embodiment, modificationof HTTP content request 266 is based upon pre-configured policiesassociated with particular IP addresses and headers and HTTP headers,and the modification can be performed in conjunction with a policyserver for the provider network. In a particular embodiment, proxyserver 240 operates to log the received HTTP content requests 226, theissued modified HTTP content requests 228, and the modifications made.Proxy server 240 further operates to detect non-HTTP traffic that isissued over TCP port 80, and to return the non-HTTP traffic to loadbalancer 230 unmodified, or to otherwise handle the non-HTTP traffic.

Load balancer 230 operates to receive the modified HTTP content request268. Based upon the modifications included in the HTTP headers, loadbalancer 230 operates to issue HTTP connection request 270 to contentorigin server 250 to open the connection between the origin server andthe load balancer. When the connection is open, load balancer 230 issuesmodified HTTP content request 272 to content origin server 250. In aparticular embodiment, modified HTTP content request 272 is the same asHTTP content request 268. In another embodiment, modified HTTP contentrequest 272 is different than modified HTTP content request 268, andload balancer 230 operates to modify modified HTTP content request 268into modified HTTP content request 272. In particular, where proxyserver 240 adds or modifies a DSCP header, load balancer 230 operates tohandle modified HTTP content request 268 according to the indicated QoSlevel. Further, where proxy server 240 provides a forwarding IP addressor keyword associated with origin server 250, load balancer 230 operatesto remove the IP address or keyword, as needed or desired.

FIGS. 3-6 illustrate various use cases of communications network 200.FIG. 3 shows a case 300 where connections between client system 210,load balancer 230, proxy server 240, and origin server 250 are closedafter the requested content is sent to the client system. Here clientsystem 210 sends a TCP connection request to load balancer 230, depictedas a SYN-SYN/ACK-ACK transaction 302, thereby opening a connectionbetween the client system and the load balancer. Load balancer 230 sendsa TCP connection request to proxy server 240, depicted as aSYN-SYN/ACK-ACK transaction 304, thereby opening a connection betweenthe load balancer and the proxy server. Client system 210 sends an HTTPcontent request, depicted as a GET request 306 to load balancer 230, andthe load balancer forwards GET request 308 to proxy server 240. Proxyserver 240 returns a modified GET request 310 to load balancer 230, andthe connection between the load balancer and the proxy server is closed312. Load balancer 230 sends a TCP connection request to origin server250, depicted as a SYN-SYN/ACK-ACK transaction 314, thereby opening aconnection between the load balancer and the origin server. Loadbalancer 230 sends the modified GET request 316 to origin server 250.Origin server 250 sends the requested content 318 to load balancer 230,and the load balancer forwards the requested content 320 to clientsystem 210. The connection between load balancer 230 and origin server250 is closed 322, and the connection between the load balancer andclient system 210 is closed 324.

FIG. 4 shows a case 400 where the connection between load balancer 230and proxy server 240 is a persistent connection 402, and the connectionbetween client system 210 and load balancer 230 is closed after therequested content is sent to the client system. Here client system 210sends a SYN-SYN/ACK-ACK transaction 404, thereby opening a connectionbetween the client system and the load balancer, and sends a GET request406 to the load balancer. Load balancer 230 forwards GET request 408 toproxy server 240, and the proxy server returns a modified GET request410 to the load balancer. Load balancer 230 sends a SYN-SYN/ACK-ACKtransaction 412 to origin server 250, thereby opening a connectionbetween the load balancer and the origin server. Load balancer 230 sendsthe modified GET request 414 to origin server 250. Origin server 250sends the requested content 416 to load balancer 230, and the loadbalancer forwards the requested content 418 to client system 210. Theconnection between load balancer 230 and origin server 250 is closed420, and the connection between the load balancer and client system 210is closed 422.

FIG. 5 shows a case 500 where the connection between load balancer 230and proxy server 240 is a persistent connection 502, and the connectionbetween client system 210 and load balancer 230 remains open formultiple content requests. Here client system 210 sends aSYN-SYN/ACK-ACK transaction 504, thereby opening a connection betweenthe client system and the load balancer, and sends a GET request 506 tothe load balancer. Load balancer 230 forwards GET request 508 to proxyserver 240, and the proxy server returns a modified GET request 510 tothe load balancer. Load balancer 230 sends a SYN-SYN/ACK-ACK transaction512 to origin server 250, thereby opening a connection between the loadbalancer and the origin server. Load balancer 230 sends the modified GETrequest 514 to origin server 250. Origin server 250 sends the requestedcontent 516 to load balancer 230, and the load balancer forwards therequested content 518 to client system 210. Client system 210 sendsanother GET request 520 to load balancer 230, and the load balancerforwards GET request 522 to proxy server 240. Proxy server 240 returnsanother modified GET request 524 to load balancer 230, and the loadbalancer sends the modified GET request 526 to origin server 250. Originserver 250 sends the requested content 528 to load balancer 230, andload balancer 230 forwards the requested content 530 to client system210. The connection between load balancer 230 and origin server 250 isclosed 532, and the connection between the load balancer and clientsystem 210 is closed 534.

FIG. 6 shows a case 600 where proxy server 240 issues a redirect inresponse to a content request. Here the connection between load balancer230 and proxy server 240 is a persistent connection 602, and clientsystem 210 sends a SYN-SYN/ACK-ACK transaction 604, thereby opening aconnection between the client system and the load balancer. Clientsystem 210 sends a GET request 606 to load balancer 230, and the loadbalancer forwards GET request 608 to proxy server 240. Proxy server 240returns a redirect response 610 to load balancer 230, the load balancerforwards the redirect response 612 to client system 210, and theconnection between the load balancer and the client system is closed614.

FIG. 7 illustrates an embodiment of a general computer system 700. Thecomputer system 700 includes instructions that are executed to cause thecomputer system to perform any one or more of the methods or computerbased functions disclosed herein. Computer system 700 may operate as astandalone device or may be connected, such as by using a network, toother computer systems or peripheral devices. Computer system 700 canoperate as a server or as a client user computer in a server-client usernetwork environment, or as a peer computer system in a peer-to-peer (ordistributed) network environment. Computer system 700 can also beimplemented as or incorporated into various devices, such as a personalcomputer (PC), a tablet PC, a set-top box(STB), a personal digitalassistant (PDA), a mobile device, a palmtop computer, a laptop computer,a desktop computer, a communications device, a wireless telephone, alandline telephone, a control system, a camera, a scanner, a facsimilemachine, a printer, a pager, a personal trusted device, a web appliance,a network router, switch or bridge, or any other machine capable ofexecuting instructions (sequential or otherwise) that specify actions tobe taken by that machine. In a particular embodiment, computer system700 can be implemented using electronic devices that provide voice,video, or data communication. Further, while computer system 700 isillustrated as a single item, the term “system” shall also be taken toinclude any collection of systems or sub-systems that individually orjointly execute a set of, or multiple sets of instructions to performone or more computer functions.

Computer system 700 includes a processor 702, a main memory 704, astatic memory 706, a video display unit 710, an input device 712, acursor control device 714, a disk drive unit 716, a signal generationdevice 718, and a network interface device 720, that can communicatewith each other via a bus 708. Processor 702 represents a centralprocessing unit (CPU), a graphics processing unit (GPU), anotherprocessing device, or a combination thereof. Video display unit 710represents a liquid crystal display (LCD), an organic light emittingdiode (OLED), a flat panel display, a solid-state display, a cathode raytube (CRT), another display device, or a combination thereof. In aparticular embodiment, input device 712 represents a keyboard, andcursor control device 714 represents a mouse. Alternatively, inputdevice 712 and cursor control device 714 can be combined with videodisplay unit 710 in the form of a touchpad or touch sensitive screen.Disk drive device 716 represents an information storage device includinga disk drive, a solid state drive (SSD), an external hard drive, anotherinformation storage device, or a combination thereof. Signal generationdevice 718 represents a speaker, a remote control unit, another device,or a combination thereof. Network interface device 720 communicates witha network 726. Disk drive device 716 includes a computer-readable medium722 for storing one or more sets of instructions 724. Additionally, mainmemory 704 and static memory 706 store one or more additional sets ofinstructions 724. The sets of instructions 724 represent programs,software, firmware, machine-executable code, other instructions, or acombination thereof. Also, instructions 724 can be embedded in a deviceof computer system 700. In a particular embodiment, instructions 724represent one or more of the methods or logic as described herein.Processor 702 operates to execute instructions 724 to perform one ormore of the methods or logic as described herein.

The previously discussed modules, devices, systems, or other elements(hereinafter “module,” can be implemented in hardware, software, or anycombination thereof. Each module may include one or more computersystems. When a module includes more than one computer system, thefunctions of the module can be distributed across the multiple computersystems in a symmetric manner, i.e., each computer system performs thesame type of tasks, or in an asymmetric manner, i.e., two computersystems of the module may perform different tasks.

The illustrations of the embodiments described herein are intended toprovide a general understanding of the structure of the variousembodiments. The illustrations are not intended to serve as a completedescription of all of the elements and features of apparatus and systemsthat utilize the structures or methods described herein. Many otherembodiments may be apparent to those of skill in the art upon reviewingthe disclosure. Other embodiments may be utilized and derived from thedisclosure, such that structural and logical substitutions and changesmay be made without departing from the scope of the disclosure.Additionally, the illustrations are merely representational and may notbe drawn to scale. Certain proportions within the illustrations may beexaggerated, while other proportions may be minimized. Accordingly, thedisclosure and the FIGS. are to be regarded as illustrative rather thanrestrictive.

The Abstract of the Disclosure is provided to comply with 37 C.F.R.§1.72(b) and is submitted with the understanding that it will not beused to interpret or limit the scope or meaning of the claims. Inaddition, in the foregoing Detailed Description of the Drawings, variousfeatures may be grouped together or described in a single embodiment forthe purpose of streamlining the disclosure. This disclosure is not to beinterpreted as reflecting an intention that the claimed embodimentsrequire more features than are expressly recited in each claim. Rather,as the following claims reflect, inventive subject matter may bedirected to less than all of the features of any of the disclosedembodiments. Thus, the following claims are incorporated into theDetailed Description of the Drawings, with each claim standing on itsown as defining separately claimed subject matter.

The above disclosed subject matter is to be considered illustrative, andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments which fall within thetrue spirit and scope of the present disclosed subject matter. Thus, tothe maximum extent allowed by law, the scope of the present disclosedsubject matter is to be determined by the broadest permissibleinterpretation of the following claims and their equivalents, and shallnot be restricted or limited by the foregoing detailed description.

What is claimed is:
 1. A load balancer comprising: a processor; and amemory including processor-executable code to at least: forward a firstcontent request from a client system to a proxy server; receive a firstmodified content request from the proxy server, wherein the firstmodified content request is based upon the first content request andincludes information identifying a first content origin server; open afirst connection with the first content origin server in response toreceiving the first modified content request; send a second modifiedcontent request based upon the first modified content request to thefirst content origin server; receive first content associated with thefirst content request from the first content origin server, wherein thefirst content is sent from the first content origin server to the loadbalancer without passing through the proxy server; and forward the firstcontent to the client system.
 2. The load balancer of claim 1, thememory further including processor-executable code to: open a secondconnection with the client system; and receive the first content requestfrom the client system in response to establishing the secondconnection.
 3. The load balancer of claim 2, the memory furtherincluding processor-executable code to: close the second connection inresponse to forwarding the first content.
 4. The load balancer of claim2, the memory further including processor-executable code to: forward asecond content request from the client system to the proxy server;receive a third modified content request from the proxy server, whereinthe third modified content request is based upon the second contentrequest and includes the information identifying the first contentorigin server; send a fourth modified content request based upon thethird modified content request to the first content origin server;receive second content associated with the second content request fromthe first content origin server, wherein the second content is sent fromthe first content origin server to the load balancer without passingthrough the proxy server; forward the second content to the clientsystem; and close the second connection in response to forwarding thesecond content.
 5. The load balancer of claim 2, the memory furtherincluding processor-executable code to: forward a second content requestfrom the client system to the proxy server; receive a redirect messagefrom the proxy server, wherein the redirect message is based upon thefirst content request; forward the redirect message to the clientsystem; and close the second connection in response to forwarding theredirect message.
 6. The load balancer of claim 1, the memory furtherincluding processor-executable code to: forward a second content requestfrom the client system to the proxy server; receive a third modifiedcontent request from the proxy server, wherein the third modifiedcontent request is based upon the second content request and includesinformation identifying a second content origin server; open a thirdconnection with the second content origin server in response toreceiving the second modified content request; send a fourth modifiedcontent request based upon the third modified content request to thesecond content origin server; receive second content associated with thesecond content request from the second content origin server, whereinthe second content is sent from the second content origin server to theload balancer without passing through the proxy server; forward thesecond content to the client system; and close the third connection inresponse to receiving the second content.
 7. The load balancer of claim1, the memory further including processor-executable code to: close thefirst connection in response to forwarding the first content.
 8. Theload balancer of claim 1, wherein the first modified content requestincludes a header that is added to the first content request by theproxy server.
 9. The load balancer of claim 8, the memory furtherincluding processor-executable code to: remove the header from the firstmodified content request to make the second modified content request.10. The load balancer of claim 8, wherein the header includes theinformation identifying the first content origin server.
 11. The loadbalancer of claim 1, wherein the first modified content request includesa first quality of service level that is different from a second qualityof service level of the first content request.
 12. A method comprising:receiving a first content request at a load balancing device of aprovider network, the first content request being received from a clientsystem; forwarding the first content request to a proxy server of theprovider network; receiving at the load balancing device a firstmodified content request from the proxy server, wherein the firstmodified content request is based upon the first content request andincludes information identifying a first content origin server; openinga first connection between the load balancing device and the firstcontent origin server in response to receiving the first modifiedcontent request; sending a second modified content request based uponthe first modified content request to the first content origin server;receiving first content associated with the second modified contentrequest from the first content origin server, wherein the first contentis sent from the first content origin server to the load balancerwithout passing through the proxy server; and forwarding the firstcontent to the client system.
 13. The method of claim 12, furthercomprising: opening a second connection with the client system; whereinreceiving the first content request from the client system is inresponse to establishing the second connection.
 14. The method of claim13, further comprising: forwarding a second content request from theclient system to the proxy server; receiving at the load balancingdevice a third modified content request from the proxy server, whereinthe third modified content request is based upon the second contentrequest and includes the information identifying the first contentorigin server; sending a fourth modified content request based upon thethird modified content request to the first content origin server;receiving second content associated with the second content request fromthe first content origin server, wherein the second content is sent fromthe first content origin server to the load balancer without passingthrough the proxy server; forwarding the second content to the clientsystem; and close the second connection in response to forwarding thesecond content.
 15. The method of claim 13, further comprising:forwarding a second content request from the client system to the proxyserver; receiving at the load balancing device a redirect message fromthe proxy server, wherein the redirect message is based upon the firstcontent request; forwarding the redirect message to the client system;and closing the second connection in response to forwarding the redirectmessage.
 16. The method of claim 12, wherein the first modified contentrequest includes a header that is added to the first content request bythe proxy server.
 17. The method of claim 16, further comprising:removing the header from the first modified content request to make thesecond modified content request.
 18. The method of claim 12, wherein thefirst modified content request includes a first quality of service levelthat is different from a second quality of service level of the firstcontent request.
 19. A proxy server of a provider network, comprising: aprocessor; and a memory including processor-executable code to at least:receive a content request from a client system; modify the contentrequest to make a modified content request; and send the modifiedcontent request to a load balancer of the provider network; wherein: themodified content request identifies a content origin server associatedwith the content request; and content associated with the contentrequest is provided to the client system from the load balancer withoutthe content passing through the proxy server.
 20. The proxy server ofclaim 19, wherein the modified content request includes a first qualityof service level that is different from a second quality of servicelevel associated with the content request.